Printing device, patterning method using the same, and method of fabricating a liquid crystal display device using the same

ABSTRACT

A printing device, a patterning method using the same and a method of fabricating an LCD device using the same are disclosed. The printing device includes a printing roll having a blanket adhered to an outer surface thereof; and an absorption nozzle to absorb solvent from the blanket. The absorption nozzle may include an absorber having a slit, a vacuum controller connected to the absorber, and a pipe connected to the vacuum controller.

This application claims the benefit of Korean Patent Application No.2006-60431 filed on Jun. 30, 2006, which is hereby incorporated byreference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display (LCD) device,and a method of forming a pattern of LCD device by printing.

2. Discussion of the Related Art

Typically, a liquid crystal display (LCD) device includes lower andupper substrates and a liquid crystal layer formed between the lower andupper substrates. The lower substrate typically includes a thin filmtransistor and a pixel electrode and the upper substrate may include alight-shielding layer, a color filter layer and a common electrode.

An LCD device is provided with various components patterned by repeatedprocesses. Photolithography is used to pattern the plurality ofcomponents in the various shapes used in the LCD device.Photolithography uses a mask having a predetermined pattern and alight-irradiation device resulting in an increase in the cost ofmanufacturing LCD devices. In addition, photolithography includesexposure and development processes that complicate the manufacturingprocess and increase manufacturing time.

To overcome the problems associated with photolithography, newpatterning methods, such as a printing method, have been developed.

In the printing method, a predetermined material is coated on a printingroll, and the printing roll coated with the predetermined material isthen rolled on a substrate to transcribe predetermined pattern onto thesubstrate. Hereinafter, a related art printing method will be describedwith reference to the accompanying drawings.

FIGS. 1A to 1C schematically illustrate a related art printing method.

First, as shown in FIG. 1A, a pattern material 20 is applied to aprinting roll 30 through a printing nozzle 10. A blanket 35 adheres tothe outer surface of printing roll 30 and is coated with the appliedpattern material 20. The blanket 35 should have properties of goodadherence to the printing roll 30 and high resistance to deformationduring the printing process. The blanket 35 is typically formed of aSi-based resin.

After coating the pattern material onto the printing roll, as shown inFIG. 1B, the printing roll 30 is rolled onto a printing plate 40 havinga plurality of protruding patterns 46 and groove patterns 43. As aresult, some 20 a of the pattern material is transcribed or transferredonto the protruding patterns 46 of printing plate 40, leaving remainingpattern material 20 b to form a predetermined pattern on the blanket 35of the printing roll 30.

Referring to FIG. 1C, the printing roll 30 is rotated on a substrate 50and the remaining pattern material 20 b on printing roll 30 istranscribed on the substrate 50, thereby forming the desired pattern onthe substrate 50.

Using the above described printing method allows omitting the exposureand development processes used in photolithography. Accordingly, theprinting method has lower fabrication cost and uses simpler processesthan do processes using photolithography, making the printing methodsuitable for use in the mass-production.

As the pattern formation of printing method is performed repeatedly, asolvent of pattern material 20 is absorbed into the blanket 35 adheringto the outer surface of printing roll 30. As a result of absorbing thesolvent, the blanket 35 may swell deforming the shape of the blanket 35.The deformation of the blanket 35 may interfere with forming a precisepattern.

For example, as shown in FIG. 2A, if during the process of rolling theblanket 35 of printing roll 30 coated with the pattern material 20 onthe printing plate 40 provided with the protruding patterns 46 andgroove patterns 43, the blanket 35 has a swollen portion, the patternmaterial 20 may contact the printing plate 40 within the groove patterns43 of the printing plate 40. As a result of the contact within thegroove patterns 43 of the printing plate 40, as shown in FIG. 2B, someof the pattern material 20 b is transferred onto the groove patterns 43in addition to the pattern material 20 a that is transcribed on theprotruding patterns. Accordingly, pattern material 20 c remaining on theblanket 35 of printing roll 30 does not include the pattern materialformed in region “A” and the desired precise pattern on the printingroll 30 is not formed.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a printing device, apatterning method using the same, and a method of fabricating a liquidcrystal display (LCD) device using the same that substantially obviatesone or more of the problems due to limitations and disadvantages of therelated art.

An advantage of the present invention is to provide a printing device toprevent a blanket adhered to a printing roll from being swollen by asolvent included with a pattern material.

Another advantage of the present invention is to provide a patterningmethod to prevent a blanket adhered to a printing roll from beingswollen by a solvent included with a pattern material.

Another advantage of the present invention is to provide a method offabricating an LCD device using the patterning method to eliminate orreduce the forming of defective pattern in the LCD device.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. These andother advantages of the invention will be realized and attained by thestructure particularly pointed out in the written description and claimshereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, a printingdevice includes a printing roll having a blanket adhered to an outersurface thereof and an absorption nozzle to absorb solvent from theblanket.

In another aspect of the present invention, a patterning methodincludes: coating a blanket adhered to an outer surface of a printingroll with a pattern material; absorbing a solvent from the blanket ofthe printing roll; rolling the printing roll on a printing plate totransfer some of the pattern material onto protrusions of the printingplate leaving a remaining pattern material on the printing roll to forma predetermined pattern on the printing roll; and rolling the printingroll on a substrate to transfer the predetermined pattern onto thesubstrate.

In another aspect of the present invention, a method of fabricating anLCD device includes: preparing first and second substrates; and forminga liquid crystal layer between the first and second substrates, whereinpreparing the first substrate includes forming a pattern on the firstsubstrate using a patterning method comprising: coating a blanketadhered to outer surface of a printing roll with a pattern material;absorbing a solvent from the blanket of printing roll; rolling theprinting roll on a printing plate to transcribe some of the patternmaterial on protrusions of the printing plate and to leave remainingpattern material on the blanket to form a predetermined pattern on theprinting roll; and rolling the printing roll on a substrate to transferthe predetermined pattern onto a substrate.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIGS. 1A to 1C are cross section views schematically illustrating arelated art printing method;

FIGS. 2A and 2B are cross section views illustrating problems of relatedart printing method;

FIG. 3 is a cross section view schematically illustrating a printingdevice according to an embodiment of the present invention;

FIGS. 4A to 4C are views illustrating an absorption nozzle of a printingdevice according to an embodiment of the present invention;

FIG. 5 is a schematic view illustrating a printing device according toanother embodiment of the present invention; and

FIGS. 6A to 6D are cross section views schematically illustrating apatterning method according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

Hereinafter, a printing device according to the present invention willbe described with reference to the accompanying drawings.

FIG. 3 schematically illustrates a printing device according to anembodiment of the present invention. FIGS. 4A to 4C are viewsillustrating an absorption nozzle according to an embodiment of thepresent invention.

As shown in FIG. 3, a printing device according to an embodiment of thepresent invention includes a rail 101, a printing roll 100, anabsorption nozzle 200, a printing nozzle 400, a printing plate 500, anda substrate 600.

A blanket 110 is adhered to an outer surface of the printing roll 100.The printing roll 100 is moved along the rail 101 to the printing nozzle400, the absorption nozzle 200, the printing plate 500, and thesubstrate 600 to form a predetermined pattern on the substrate 600.

The printing nozzle 400 applies a pattern material to the printing roll100. The printing plate 500 is includes a plurality of protrusions 510.As the printing roll 100 is rolled on the printing plate 500, some ofthe pattern material is transferred or transcribed onto the protrusions510 of printing plate 500, leaving a desired pattern on the printingroll 100 formed of the pattern material remaining of the printing roll100. A cleaning device 700 is used to remove some or all of the patternmaterial transferred to the protrusions 510 of printing plate 500 afterrolling the printing roll 100 on the printing plate 500.

The absorption nozzle 200 absorbs a solvent from the blanket 110 ofprinting roll 100. The absorption nozzle 200 will be explained in detailwith reference to FIGS. 4A and 4C.

As shown in FIG. 4A, the absorption nozzle 200 includes an absorber 210,a vacuum controller 230 connected to the absorber 210, and a pipe 250connected to the vacuum controller 230. The absorber 210 absorbs thesolvent from the blanket 110 of printing roll 100 by application of avacuum. The curvature of absorber 210 may be identical to orsubstantially the same as the curvature of printing roll 100. In thiscase, the entire area of the absorber 210 is maintained at a constantinterval from the printing roll 100. Accordingly, it is possible toincrease the area of absorber 210 applied to the surface of the printingroll, and to reinforce the absorption efficiency owing to the increasedflow of vacuum pressure. The vacuum controller 230 controls the vacuumpressure applied to the absorber 210. The pipe 250 connects a source ofvacuum to the absorber 210 for applying the vacuum pressure. A vacuumdevice may be provided at one end of the pipe 250 to supply the vacuumpressure.

In order to move the absorption nozzle 200 up and down or to move theabsorption nozzle 200 towards or away from the absorption nozzle 200, amoving device 270 is connected to the absorption nozzle 200. The movingdevice 270 includes an absorption nozzle mover 272 connected to theabsorption nozzle 200 and a driver 274 to drive the absorption nozzlemover 272. For example, the driver 274 may include a servomotor or ahydraulic cylinder.

Referring to FIGS. 4B and 4C, a slit 220 is formed in the absorber 210,and a regulator 240 is formed in the vacuum controller 230, whereby theregulator 240 controls the vacuum pressure applied to the slit 220.Accordingly, as the vacuum pressure controlled by the regulator 240 isapplied through the slit 220, the absorption nozzle 200 absorbs solventfrom the blanket 110 of printing roll 100. The slit 220 may include aplurality of sub-slits 220 a, 220 b, 220 c and 220 d, and the regulator240 may include a plurality of sub-regulators 240 a, 240 b, 240 c and240 d to respectively regulate the vacuum pressure applied to each ofthe sub-slits 220 a, 220 b, 220 c and 220 d.

When applying the vacuum pressure through the sub-slits 220 a and 220 d,the vacuum pressure at the side positioned sub-slits near the ends ofthe slit 220 (e.g. sub-lists 220 a and 220 d) may be more stronglyinfluenced by the permeation of air external to the absorber than thevacuum pressure at centrally-positioned sub-slits (e.g. as 220 a and 220d). Accordingly, the applied vacuum pressure (measures as the amount ofpressure below atmospheric pressure) may be higher at theside-positioned sub-slits than at the centrally-positioned sub-slits, tothereby uniformly maintain the absorption intensity of vacuum pressure.

FIG. 5 schematically illustrates a printing device according to anotherembodiment of the present invention.

As shown in FIG. 5, the printing device according to another embodimentof the present invention includes a rail 101, a printing roll 100, anabsorption nozzle 200, an air knife 300, a printing nozzle 400, aprinting plate 500 and a substrate 600.

The printing device of FIG. 5 differs from the printing deviceillustrated in FIG. 3 primarily in that the printing device of FIG. 5includes the air knife 300. Components in the printing device of FIG. 5identical in structure to those of the printing device of FIG. 3 haveidentical reference numbers, and a detailed explanation of thosecomponents will be omitted.

After the absorption nozzle 200 absorbs solvent from the blanket 110 ofprinting roll 100, the air knife 300 supplies air to the blanket 110. Asa result, the solvent remaining in the blanket 110 of printing roll 100is evaporated so that the swelling of the blanket 110 of printing roll100 due to solvent is eliminated or reduced.

In the embodiment illustrated in FIG. 5 only a single air knife 300 isshown. However, the printing device may include two or more air knives.

Hereinafter, a patterning method according to the present invention willbe described as follows with reference to FIGS. 6A to 6D.

First, as shown in FIG. 6A, the pattern material 150 is applied to theblanket 110 of printing roll 100 through the printing nozzle 400. Inother words, the blanket 110 of printing roll 100 is coated with thepattern material 150.

Next, as shown in FIG. 6B, solvent absorbed in the blanket 110 ofprinting roll 100 is absorbed from the blanket 110. The process ofabsorbing solvent from the blanket 110 may be performed using theabsorption nozzle 200. The absorbing nozzle is moved toward the printingroll 100 by the moving device 270 that includes an absorption nozzlemover 272 and a driver 274.

The absorption nozzle 200 includes the absorber having a slit, thevacuum controller connected to the absorber, and the pipe connected tothe vacuum controller as described above with reference to FIGS. 4A to4C. Accordingly, the detailed explanation for the absorption nozzle andthe operation thereof will not be repeated.

In the process of absorbing the solvent from the blanket 110 by theabsorption nozzle 200, a plurality of regulators may be controlled suchthat the vacuum pressure applied to the side-positioned sub-slits ishigher than the vacuum pressure applied to the centrally-positionedsub-slits. After completing the solvent absorption process, the movingdevice 270 moves the absorption nozzle 200 away from the printing roll100, so that the absorption nozzle 200 is separated from the printingroll 100.

A process of evaporating solvent from the blanket 100 using at least oneair knife 300 may be performed in addition to or in lieu of the processof absorbing solvent from the blanket 110 using the absorption nozzle200.

As shown in FIG. 6C, the printing roll 100 is rolled on the printingplate 500, and some of the pattern material 150 a on the printing rollis transferred onto the protrusions 510 of printing plate 500. Thus, thepredetermined pattern 150 b is formed on the printing roll 100 by theremaining pattern material.

As shown in FIG. 6D, as the printing roll 100 is rolled on the substrate600, the predetermined pattern 150 b of printing roll 100 is transcribedor transferred onto the substrate 600. After completing the patterntransfer process, an additional process of cleaning the printing plate500 may be carried out.

Hereinafter, a method of fabricating an LCD device according to thepresent invention will be explained as follows.

First and second substrates are prepared. The first substrate isprepared by forming a black matrix layer to prevent the light leakage,forming a color filter layer on the black matrix layer, and forming acommon electrode on the color filter layer. The second substrate isprepared by forming a thin film transistor including: a gate electrode,a semiconductor layer, and source and drain electrodes on a transparentsubstrate, and forming a pixel electrode electrically connected to thedrain electrode of thin film transistor.

When preparing the first substrate, the black matrix layer and the colorfilter layer may be formed using the patterning method described abovewith reference to FIGS. 6A-6D.

A liquid crystal layer is formed between the first and secondsubstrates.

The process of forming the liquid crystal layer may be classified into aliquid crystal injection method and a liquid crystal dropping method.

When the liquid crystal injection method is used, a sealant having aninlet is formed on one of the first and second substrates, and then thefirst and second substrates are bonded to each other. Thereafter, liquidcrystal is injected into a space between the first and second substratesthrough the inlet.

When the liquid crystal dropping method is used, a sealant having noinlet is formed on one of the first and second substrates, and thenliquid crystal is dropped onto one of the first and second substrates.Thereafter, the first and second substrates are bonded to each other.

Accordingly, the printing device according to the present invention, thepatterning method using the same, and the method of fabricating the LCDdevice using the printing device have the following advantages.

In the printing device according to the present invention, theabsorption nozzle absorbs solvent from the blanket of printing roll.Thus, it is possible to prevent or reduce swelling of the blanket due tothe solvent, thereby preventing forming a defective pattern and toreinforce the absorption efficiency owing to the increased flow ofvacuum pressure. And the applied vacuum pressure may be higher at theside-positioned sub-slits than at the centrally-positioned sub-slits, tothereby uniformly maintain the absorption intensity of vacuum pressure.

In addition to the process of absorbing solvent from the blanket ofprinting roll using the absorption nozzle, an additional process ofevaporating solvent from the blanket using an air knife may beperformed, to enhance the removal of solvent from the blanket to preventor reduce swelling of the blanket due to solvent.

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A patterning method comprising: coating a blanket adhered to an outersurface of a printing roll with a pattern material; absorbing a solventfrom the blanket of the printing roll; evaporating the solvent from theblanket by supplying air to the blanket of the printing roll; rollingthe printing roll on a printing plate to transfer some of the patternmaterial onto protrusions of the printing plate leaving a remainingpattern material on the printing roll to form a predetermined pattern onthe printing roll; and rolling the printing roll on a substrate totransfer the predetermined pattern onto the substrate, and whereinabsorbing the solvent from the blanket of the printing roll is performedusing an absorption nozzle that includes an absorber including a slit, avacuum controller connected to the absorber, and a pipe connected to thevacuum controller.
 2. The patterning method of claim 1, wherein coatingthe blanket adhered to the outer surface of the printing roll with thepattern material is performed using a printing nozzle.
 3. The patterningmethod of claim 1, wherein a curvature of the absorber is substantiallyidentical to a curvature of the printing roll.
 4. The patterning methodof claim 1, wherein the slit formed in the absorber includes a pluralityof sub-slits and the vacuum controller includes a plurality ofregulators to regulate vacuum pressure applied to a respective sub-slitof the plurality of sub-slits.
 5. The patterning method of claim 4,including controlling the plurality of regulators such that the vacuumpressure applied to side-positioned sub-slits of the plurality ofsub-slits is higher than the vacuum pressure applied tocentrally-positioned sub-slits of the plurality of sub-slits.
 6. Thepatterning method of claim 1, further comprising moving the absorptionnozzle towards the printing roll and away from the printing roll.
 7. Thepatterning method of claim 6, wherein moving the absorption nozzle isperformed using a moving device that includes an absorption nozzle moverconnected to the absorption nozzle and a driver to drive the absorptionnozzle mover.
 8. The patterning method of claim 1, wherein evaporatingsolvent from the blanket is performed using at least one air knife. 9.The patterning method of claim 1, further comprising cleaning theprinting plate after rolling the printing roll on the substrate totransfer the predetermined pattern onto the substrate.